Compress images
Smaller files, same picture. Real codecs (MozJPEG and oxipng) running in your browser, not a generic canvas re-export.
Compress image
Drop a batch of JPGs or PNGs. Pick a JPG quality on the slider; PNGs always run lossless. The result card shows you the exact savings per file and a roll-up across the batch.
Open the compressor →Why this is different from a quality slider in Photoshop or Preview
The browser’s built-in JPG encoder (the one your OS reaches for when you “Save As JPG”) ships baseline quantization tables and no progressive scan. MozJPEG, the encoder under the hood here, adds trellis quantization, progressive scans, and tuned Q tablesthat consistently produce 20–35% smaller files at the same visual quality. It’s the same encoder Squoosh uses, the same one many CDNs run server-side. We just run it in your browser instead.
For PNGs we use oxipng at optimization level 2, lossless. It probes different filter strategies and zlib levels to find the smallest representation that still decodes to the exact same pixels. Savings depend on how poorly the source was originally encoded; expect 10–30% on photo-heavy PNGs and 30–50% on PNGs with limited color palettes (screenshots, charts, line art).
Lossy PNG palette quantization (think pngquant, the technique that shrinks photographic PNGs by 60–80%) is on the roadmap. Until then, photographic PNGs usually compress further if you convert them to JPG first.
Related categories
Your files never leave your device
MozJPEG and oxipng both ship as small WebAssembly modules that load on first compress and cache aggressively. Nothing is uploaded; verify in DevTools → Network. Read the privacy verification guide.